Demystifying remote witness participation in CAT claims

Witness evidence can play an important role in competition litigation, as the witnesses called are often uniquely placed to speak first-hand about the facts or evidence relevant to the claim. Many of the cartel and abuse of dominance claims litigated before the UK Competition Appeal Tribunal (“CAT”) are multi-jurisdictional, and the witnesses called to give evidence may be located outside of the UK. While there are clear time and cost savings in having these witnesses testify remotely, parties should be aware of any legal or diplomatic barriers in place in the country where the witness is based. This article examines the relevant rules for obtaining evidence before the CAT from witnesses based abroad and offers practical guidance on navigating this little-known aspect of cross-border litigation.

Witness evidence in competition claims

In competition claims where there is no prior binding infringement decision by a regulator, the claimant will need to use the evidence available to demonstrate it is more likely than not that a breach of competition law has occurred. This task may be complicated as a result of information asymmetry, a common feature in most competition claims. Further, for historic claims, there is a greater risk that the relevant evidence is fragmentary or inaccessible, particularly if the evidence was only available in a hard copy format. It is also challenging to find or decipher evidence in claims alleging cartel activity, as cartels are usually secretive in nature, and cartel members will go to great lengths to keep their conduct hidden.[1]

First-hand accounts from witnesses can therefore significantly influence the credibility of each party’s position, as it provides the CAT with the real-world context underpinning the market or a party’s transactions and conduct. Recent judgments have criticised or drawn adverse inferences from the failure of defendants to call witnesses who could talk about the existence or scope of the alleged cartel activity.[2] Securing testimony from relevant witnesses can therefore be critical in establishing, or defending against, the competition infringement allegations.

If a party intends to call a witness, the CAT’s Guide to Proceedings 2015 directs the parties to take “all possible steps to secure the attendance of that witness in person”.[3] However, the CAT also has the power to allow witnesses to give evidence remotely,[4] and has done so in numerous cases.[5] If a witness giving evidence remotely is based outside the UK, the responsibility is on the party calling the witness to comply with any legal or diplomatic requirements.

The legislative landscape

Historically, obtaining evidence from a witness located in a different country was largely dependent on the local laws of the foreign nation. Difficulties accessing evidence abroad were particularly evident between common law and civil law countries. While the taking of evidence by the agents of a foreign court (such as a consul or commissioner) would generally be permissible in common law countries, civil law jurisdictions considered this to be an infringement of their sovereignty.[6]

On 18 March 1970, the Hague Convention on the Taking of Evidence Abroad in Civil or Commercial Matters (“Hague Evidence Convention”) was signed to bridge the differences between the common law and civil law approaches to obtaining evidence for foreign proceedings.[7] The Hague Evidence Convention allows courts located in signatory states to send evidence requests to a single designated “central authority” if the evidence sought is located in another signatory state. Described as “one of the most successful of international conventions in the field of civil procedure”, the treaty aimed to provide a simple, effective, and inexpensive procedure for obtaining evidence abroad for use in civil litigation.[8] The UK ratified the Hague Evidence Convention in 1976. Currently, over 60 other countries, including the US, China, India and most of Europe, have also adopted it. 

The process of obtaining evidence within the EU was later harmonised by Regulation 1206/2001, which came into effect on 28 May 2001. The Regulation introduced an EU-wide system for national courts to directly send evidence-taking requests to courts in other member states. By allowing courts in EU member states to bypass the diplomatic channels and central authorities, this process simplified and accelerated evidence-taking within the EU.[9]

Regulation 1206/2001 mandated reciprocity between EU member states. That meant that the scheme no longer included the UK once it ceased to be a member state following its withdrawal from the EU on 31 December 2020.[10] The Hague Evidence Convention is therefore now the applicable means by which the UK civil courts can take evidence from witnesses located in EU member states – excluding Ireland, Belgium, and Austria, which have not yet ratified the Hague Evidence Convention. In respect of countries that have not yet ratified the Hague Evidence Convention – which includes other notable opt-outs such as Canada, Pakistan, Nigeria, and the United Arab Emirates – parties can consult a dedicated team at the UK Foreign, Commonwealth & Development Office for advice.[11]

Obtaining witness evidence for use in UK proceedings via the Hague Evidence Convention

Chapters I and II of the Hague Evidence Convention establish the methods of obtaining evidence from witnesses.

Chapter I of the Hague Evidence Convention sets out the letters of request procedure. This is a formal route that involves a judicial authority (for example, the English High Court’s Foreign Process Section) sending a request to the judicial authorities in the country where the witness is based, which then executes the request.

Chapter II of the Hague Evidence Convention sets out an alternative procedure whereby diplomatic officers, consular agents, and private commissioners oversee the taking of evidence. The requesting court issues a “Request for Assistance” addressed to the relevant designated authority in the country where the witness is based. Once approved, the official or commissioner may oversee the evidence taking process in accordance with local laws and any conditions set by the designated authority.

Taking remote evidence from witnesses based abroad

If a witness is located abroad, no issues under international law will arise if they are willing to travel to the UK to give evidence. However, this may not always be practical or possible for the witness in question. Videoconferencing offers clear savings in time and cost when taking evidence remotely. Given the growth of videoconferencing in most businesses, in particular following the COVID-19 pandemic, a witness may also presume – or even insist – that they will give their testimony from their country of residence.

There may also be circumstances where the country in which the witness is located imposes civil or criminal sanctions if evidence is gathered within their jurisdiction without the approval from the relevant state. For instance, French nationals, residents, or directors of French companies may incur criminal liability for giving remote oral or written evidence in foreign proceedings unless prior approval is sought under judicial cooperation rules such as the Hague Evidence Convention.[12] The prohibition applies even where the witness is voluntarily giving evidence. Although prosecutions are rare in practice,[13] the party calling the witness will nonetheless want to protect their witness and ensure the right procedure is followed.

Practical considerations

As a starting point, it is advisable to plan as early as possible for any witness who might need to testify from a country other than the UK. If a party cannot show the CAT that there are legal or diplomatic barriers to the taking of evidence, the CAT may refuse permission for the evidence to be heard remotely, or issue costs sanctions for any delays to the proceedings.

In Interdigital Technology Corp v Lenovo Group Ltd,[14] the English High Court considered whether the claimants’ testifying expert could give evidence remotely from Germany in the event he could not travel due to COVID-19 related travel restrictions. The High Court found a real risk that allowing the claimants’ expert to testify remotely from Germany could breach German law. The judgment referenced a German Federal Supreme Court judgment, which established that the taking of video evidence abroad for use in a German trial affected the territorial sovereignty of the foreign state. In light of this German court ruling, the High Court concluded it was likely that the reverse situation (i.e. a court outside of Germany taking remote evidence from Germany) would raise an issue of German sovereignty. The claimants’ expert could therefore only give evidence by video link from Germany if permission was received from the relevant German authority.

Where the country in which the witness is located is a signatory to the Hague Evidence Convention, an important consideration will be which procedure works best for their circumstances. The letter of request route under Chapter I ensures compliance with local laws and provides a high degree of legal formality, but it can be slow and cumbersome, often taking several months to process due to bureaucratic hurdles. Using a private commissioner under the Chapter II procedure offers a more flexible and expedited approach, and requires less involvement from the local courts. That being said, the extent to which it accelerates the evidence taking process is highly dependent on the speed of the designated authority receiving the Request for Assistance. Additionally, in almost all cases, the use of a private commissioner will only be available where the witness evidence is given voluntarily.[15]

In addition, signatory states may also impose additional requirements or restrictions. Parties should therefore also refer to the Hague Convention’s website for any such country-specific requirements, whether under the Chapter I or Chapter II procedures.

It is important to keep in mind that permission for witnesses to remotely attend CAT hearings is a case management decision. Even where obtaining the consent of the foreign state is not an issue, the CAT will have regard to the overriding objective and may nonetheless refuse permission if allowing evidence given from abroad will affect the fair and efficient disposal of the litigation. The CAT will likely seek to ensure that the necessary practical arrangements can be made, such as access to a reliable internet connection, webcam and a quiet space; remote access to the hearing bundle; and availability to attend a test-run prior to the hearing.

While the CAT has yet to issue any ruling or guidance on obtaining evidence from overseas witnesses, the CAT has in multiple cases issued Requests for Assistance appointing private commissioners under Chapter II of the Hague Evidence Convention.[16] The orders published in these cases helpfully set out the directions followed by the parties to validly produce the witness evidence.

Guidance issued by other courts and tribunals can also contain practical tips on how to manage the remote witness evidence process. For example, Annex 3 of CPR Part 34 sets out video conferencing guidance partially based on Australian federal court protocols. Additionally, in January 2025, the Employment Tribunal in England and Wales issued updated guidance on taking evidence from persons located abroad.[17]

Conclusion

By planning early and following international conventions and national regulations, litigating parties will be well placed to effectively secure important witness testimony without requiring the witness to be physically present in the UK. While timely foreign approvals are important, parties should also be prepared to demonstrate to the CAT that remote witness testimony will not disrupt or adversely affect the litigation.